Increased production of 12/15 lipoxygenase eicosanoids accelerates monocyte/endothelial interactions in diabetic db/db mice

J Biol Chem. 2003 Jul 11;278(28):25369-75. doi: 10.1074/jbc.M301175200. Epub 2003 May 6.


Atherosclerosis is a major complication of diabetes. Up to 16 weeks of age, the db/db mouse is insulin-resistant and hyperglycemic and is a good model of Type 2 diabetes. After approximately 16 weeks of age, the mice develop pancreatic beta cell failure that can progress to a Type 1 diabetes phenotype. We have previously shown that glucose increases production of endothelial 12/15 lipoxygenase (12/15LO) products in vitro. In young 10-week-old Type 2 diabetic db/db mice, we found significant elevations in levels of urinary 12/15LO products, 12S-hydroxyeicosatetraenoic acid (12S-HETE) and 13S-hydroxyoctadecaenoic acid (13S-HODE) in vivo compared with C57BLKS/J mice. Using isolated primary aortic endothelial cells (ECs) from db/db mice and WEHI78/24 mouse monocyte cells in static adhesion assays, we found increased WEHI monocyte adhesion to db/db ECs (14 +/- 2 monocytes/field for db/db ECs versus 4 +/- 1 monocytes/field for C57BLKS/J ECs, p < 0.002). Thus, ECs from db/db mice appear to be "pre-activated" to bind monocytes. Analysis of db/db ECs revealed a 2-fold elevation in 12/15LO protein compared with C57BLKS/J EC. To determine that 12/15LO products were responsible for the increased monocyte adhesion observed with db/db ECs, we inhibited expression of murine 12/15LO using either an adenovirus expressing a ribozyme to 12/15LO (AdRZ) or with the 12/15LO inhibitor cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate. Treatment of db/db ECs for 48 h with AdRZ or 4 h with 10 microm cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate significantly reduced monocyte adhesion to db/db endothelium (p < 0.009). Thus, inhibition of the murine 12/15LO in db/db mice significantly reduced monocyte/endothelial interactions. We also found that adhesion of monocytes to diabetic db/db ECs was mediated by interactions of alpha4beta1 integrin on monocytes with endothelial vascular cell adhesion molecule 1 and connecting segment 1 fibronectin and interactions of beta2 integrins with endothelial intercellular adhesion molecule 1. In summary, regulation of the 12/15LO pathway is important for mediating early vascular changes in diabetes. Modulation of the 12/15LO pathway in the vessel wall may provide therapeutic benefit for early vascular inflammatory events in diabetes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / urine
  • Animals
  • Aorta / metabolism
  • Arachidonate 12-Lipoxygenase / biosynthesis*
  • Arachidonate 15-Lipoxygenase / biosynthesis*
  • Cell Adhesion
  • Eicosanoids / metabolism
  • Endothelium, Vascular / metabolism*
  • Fibronectins / metabolism
  • Flow Cytometry
  • Immunoassay
  • Inflammation
  • Islets of Langerhans / metabolism
  • Linoleic Acids / urine
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / metabolism
  • Monocytes / metabolism*
  • Phenotype
  • Reactive Oxygen Species


  • Eicosanoids
  • Fibronectins
  • Linoleic Acids
  • Reactive Oxygen Species
  • 13-hydroxy-9,11-octadecadienoic acid
  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
  • Arachidonate 12-Lipoxygenase
  • Arachidonate 15-Lipoxygenase