Selective inhibition of 12-lipoxygenase protects islets and beta cells from inflammatory cytokine-mediated beta cell dysfunction.

Therapeutic Approaches

Abstract

AIMS/HYPOTHESIS: Islet inflammation leads to loss of functional pancreatic beta cell mass. Increasing evidence suggests that activation of 12-lipoxygenase leads to inflammatory beta cell loss. This study evaluates new specific small-molecule inhibitors of 12-lipoxygenase for protecting rodent and human beta cells from inflammatory damage. METHODS: Mouse beta cell lines and mouse and human islets were treated with inflammatory cytokines IL-1β, TNFα and IFNγ in the absence or presence of novel selective 12-lipoxygenase inhibitors. Glucose-stimulated insulin secretion (GSIS), gene expression, cell survival and 12-S-hydroxyeicosatetraenoic acid (12-S-HETE) levels were evaluated using established methods. Pharmacokinetic analysis was performed with the lead inhibitor in CD1 mice. RESULTS: Inflammatory cytokines led to the loss of human beta cell function, elevated cell death, increased inflammatory gene expression and upregulation of 12-lipoxygenase expression and activity (measured by 12-S-HETE generation). Two 12-lipoxygenase inhibitors, Compounds 5 and 9, produced a concentration-dependent reduction of stimulated 12-S-HETE levels. GSIS was preserved in the presence of the 12-lipoxygenase inhibitors. 12-Lipoxygenase inhibition preserved survival of primary mouse and human islets. When administered orally, Compound 5 reduced plasma 12-S-HETE in CD1 mice. Compounds 5 and 9 preserved the function and survival of human donor islets exposed to inflammatory cytokines. CONCLUSIONS/INTERPRETATION: Selective inhibition of 12-lipoxygenase activity confers protection to beta cells during exposure to inflammatory cytokines. These concept validation studies identify 12-lipoxygenase as a promising target in the prevention of loss of functional beta cells in diabetes.

Authors

Taylor-Fishwick, David A; Weaver, Jessica; Glenn, Lindsey; Kuhn, Norine; Rai Bantukallu, Ganesha; Jadhav, Ajit; Simeonov, Anton; Dudda, Angela; Schmoll, Dieter; Holman, Theodore R; Maloney, David J; Nadler, Jerry L;

Keywords

  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/ metabolism
  • Animals
  • Apoptosis/ drug effects
  • Arachidonate 12-Lipoxygenase/ metabolism
  • Cell Line
  • Cell Survival/ drug effects
  • Enzyme Inhibitors/ pharmacology
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • In Vitro Techniques
  • Insulin-Secreting Cells/ drug effects
  • Insulin-Secreting Cells/ metabolism
  • Interleukin-1beta/ metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Real-Time Polymerase Chain Reaction
  • Tumor Necrosis Factor-alpha/ metabolism

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