Signaling proteins associated with diabetic-induced exocrine pancreatic insufficiency in rats

Rekha Patel, Philip Atherton, Henning Wackerhage, Jaipaul Singh

Research output: Contribution to journalBook/Film/Article review

5 Citations (Scopus)

Abstract

Diabetes mellitus (DM) is associated with pancreatic atrophy and compromised digestion of carbohydrates as a result of exocrine pancreatic insufficiency and lower alpha-amylase synthesis and secretion. The reduced production of digestive enzymes is likely to be caused by deregulated protein metabolism. The relative concentrations and phosphorylation of signaling proteins associated with protein translation, such as PKB, p70S6K1, 4E-BP1, ERK1/2, and also some of those implicated in protein breakdown, such as ubiquitin and NF-kappa B, in the pancreas of streptozotocin (STZ)-induced type 1 diabetic pancreas were measured using Western blotting. There were significant decreases in the levels of total PKB, p70S6K, 4E-BP1, ERK1/2, and NF-kappa B in the diabetic pancreas compared to control. In contrast, the phosphorylation of p70S6K1, 4E-BP1, ERK1/2, and protein ubiquitination increased significantly compared to controls. Together, these results indicate that STZ-induced DM leads to reduced levels of enzymes mediating protein synthesis while their phosphorylation is actually increased, perhaps in an attempt to maintain protein homeostasis, which is further compromised by heightened ubiquitin-dependent protein breakdown. It is likely that these factors are responsible for pancreatic atrophy, enzyme synthesis, and net protein loss in DM.

Original languageEnglish
Pages (from-to)490-502
Number of pages13
JournalAnnals of the New York Academy of Sciences
Volume1084
Issue number1
DOIs
Publication statusPublished - Nov 2006

Keywords

  • diabetes mellitus
  • rat
  • pancreas
  • signaling proteins
  • acinar cells
  • Insulin
  • secretion
  • phosphorylation
  • acetylcholine
  • mechanism
  • mellitus
  • amylase
  • kinase
  • MTOR

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