Thioredoxin-interacting protein deficiency induces Akt/Bcl-xL signaling and pancreatic beta-cell mass and protects against diabetes

FASEB J. 2008 Oct;22(10):3581-94. doi: 10.1096/fj.08-111690. Epub 2008 Jun 13.


Pancreatic beta-cell loss through apoptosis represents a key factor in the pathogenesis of diabetes; however, no effective approaches to block this process and preserve endogenous beta-cell mass are currently available. To study the role of thioredoxin-interacting protein (TXNIP), a proapoptotic beta-cell factor we recently identified, we used HcB-19 (TXNIP nonsense mutation) and beta-cell-specific TXNIP knockout (bTKO) mice. Interestingly, HcB-19 mice demonstrate increased adiposity, but have lower blood glucose levels and increased pancreatic beta-cell mass (as assessed by morphometry). Moreover, HcB-19 mice are resistant to streptozotocin-induced diabetes. When intercrossed with obese, insulin-resistant, and diabetic mice, double-mutant BTBRlep(ob/ob)txnip(hcb/hcb) are even more obese, but are protected against diabetes and beta-cell apoptosis, resulting in a 3-fold increase in beta-cell mass. Beta-cell-specific TXNIP deletion also enhanced beta-cell mass (P<0.005) and protected against diabetes, and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) revealed a approximately 50-fold reduction in beta-cell apoptosis in streptozotocin-treated bTKO mice. We further discovered that TXNIP deficiency induces Akt/Bcl-xL signaling and inhibits mitochondrial beta-cell death, suggesting that these mechanisms may mediate the beta-cell protective effects of TXNIP deficiency. These results suggest that lowering beta-cell TXNIP expression could serve as a novel strategy for the treatment of type 1 and type 2 diabetes by promoting endogenous beta-cell survival.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Carrier Proteins / genetics*
  • Cell Count
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / genetics
  • Diabetes Mellitus, Type 1 / genetics*
  • Diabetes Mellitus, Type 1 / pathology
  • Diabetes Mellitus, Type 2 / genetics*
  • Diabetes Mellitus, Type 2 / pathology
  • Hypoglycemia
  • Insulin-Secreting Cells / metabolism
  • Insulin-Secreting Cells / pathology*
  • Mice
  • Mice, Knockout
  • Obesity / complications
  • Obesity / pathology
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction
  • Thioredoxins / genetics*
  • bcl-X Protein / metabolism*


  • Carrier Proteins
  • Txnip protein, mouse
  • bcl-X Protein
  • Thioredoxins
  • Proto-Oncogene Proteins c-akt