General control nonderepressible 2 deletion predisposes to asparaginase-associated pancreatitis in mice

Am J Physiol Gastrointest Liver Physiol. 2016 Jun 1;310(11):G1061-70. doi: 10.1152/ajpgi.00052.2016. Epub 2016 Mar 11.


Treatment with the antileukemic agent asparaginase can induce acute pancreatitis, but the pathophysiology remains obscure. In the liver of mice, eukaryotic initiation factor 2 (eIF2) kinase general control nonderepressible 2 (GCN2) is essential for mitigating metabolic stress caused by asparaginase. We determined the consequences of asparaginase treatment on the pancreata of wild-type (WT, GCN2-intact) and GCN2-deleted (ΔGcn2) mice. Mean pancreas weights in ΔGcn2 mice treated with asparaginase for 8 days were increased (P < 0.05) above all other groups. Histological examination revealed acinar cell swelling and altered staining of zymogen granules in ΔGcn2, but not WT, mice. Oil Red O staining and measurement of pancreas triglycerides excluded lipid accumulation as a contributor to acini appearance. Instead, transmission electron microscopy revealed dilatation of the endoplasmic reticulum (ER) and accumulation of autophagic vacuoles in the pancreas of ΔGcn2 mice treated with asparaginase. Consistent with the idea that loss of GCN2 in a pancreas exposed to asparaginase induced ER stress, phosphorylation of protein kinase R-like ER kinase (PERK) and its substrate eIF2 was increased in the pancreas of asparaginase-treated ΔGcn2 mice. In addition, mRNA expression of PERK target genes, activating transcription factors 4, 3, and 6 (Atf4, Atf3, and Atf6), fibroblast growth factor 21 (Fgf21), heat shock 70-kDa protein 5 (Hspa5), and spliced Xbp1 (sXbp1), as well as pancreas mass, was elevated in the pancreas of asparaginase-treated ΔGcn2 mice. Furthermore, genetic markers of oxidative stress [sirtuin (Sirt1)], inflammation [tumor necrosis factor-α (Tnfα)], and pancreatic injury [pancreatitis-associated protein (Pap)] were elevated in asparaginase-treated ΔGcn2, but not WT, mice. These data indicate that loss of GCN2 predisposes the exocrine pancreas to a maladaptive ER stress response and autophagy during asparaginase treatment and represent a genetic basis for development of asparaginase-associated pancreatitis.

Keywords: amino acid response; endoplasmic reticulum stress; eukaryotic initiation factor 2; protein kinase R-like ER kinase; unfolded protein response.

MeSH terms

  • Acinar Cells / drug effects
  • Acinar Cells / metabolism
  • Acinar Cells / pathology
  • Animals
  • Asparaginase / toxicity
  • Autophagy
  • Endoplasmic Reticulum Chaperone BiP
  • Endoplasmic Reticulum Stress
  • Female
  • Fibroblast Growth Factors / genetics
  • Fibroblast Growth Factors / metabolism
  • Gene Deletion*
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Pancreas / cytology
  • Pancreas / metabolism
  • Pancreatitis / etiology
  • Pancreatitis / genetics*
  • Pancreatitis / metabolism
  • Pancreatitis-Associated Proteins
  • Protein Serine-Threonine Kinases / genetics*
  • Protein Serine-Threonine Kinases / metabolism
  • Sirtuin 1 / genetics
  • Sirtuin 1 / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Triglycerides / metabolism
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • X-Box Binding Protein 1 / genetics
  • X-Box Binding Protein 1 / metabolism
  • eIF-2 Kinase / metabolism


  • Endoplasmic Reticulum Chaperone BiP
  • HSPA5 protein, human
  • Heat-Shock Proteins
  • Hspa5 protein, mouse
  • Pancreatitis-Associated Proteins
  • REG3A protein, human
  • Transcription Factors
  • Triglycerides
  • Tumor Necrosis Factor-alpha
  • X-Box Binding Protein 1
  • Xbp1 protein, mouse
  • fibroblast growth factor 21
  • Fibroblast Growth Factors
  • Eif2ak4 protein, mouse
  • PERK kinase
  • Protein Serine-Threonine Kinases
  • eIF-2 Kinase
  • Sirt1 protein, mouse
  • Sirtuin 1
  • Asparaginase