Inhibition of DYRK1A Stimulates Human β-Cell Proliferation

Diabetes. 2016 Jun;65(6):1660-71. doi: 10.2337/db15-1127. Epub 2016 Mar 7.

Abstract

Restoring functional β-cell mass is an important therapeutic goal for both type 1 and type 2 diabetes (1). While proliferation of existing β-cells is the primary means of β-cell replacement in rodents (2), it is unclear whether a similar principle applies to humans, as human β-cells are remarkably resistant to stimulation of division (3,4). Here, we show that 5-iodotubercidin (5-IT), an annotated adenosine kinase inhibitor previously reported to increase proliferation in rodent and porcine islets (5), strongly and selectively increases human β-cell proliferation in vitro and in vivo. Remarkably, 5-IT also increased glucose-dependent insulin secretion after prolonged treatment. Kinome profiling revealed 5-IT to be a potent and selective inhibitor of the dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) and cell division cycle-like kinase families. Induction of β-cell proliferation by either 5-IT or harmine, another natural product DYRK1A inhibitor, was suppressed by coincubation with the calcineurin inhibitor FK506, suggesting involvement of DYRK1A and nuclear factor of activated T cells signaling. Gene expression profiling in whole islets treated with 5-IT revealed induction of proliferation- and cell cycle-related genes, suggesting that true proliferation is induced by 5-IT. Furthermore, 5-IT promotes β-cell proliferation in human islets grafted under the kidney capsule of NOD-scid IL2Rg(null) mice. These results point to inhibition of DYRK1A as a therapeutic strategy to increase human β-cell proliferation.

Publication types

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

MeSH terms

  • Animals
  • Cell Proliferation / drug effects*
  • Cell Proliferation / genetics
  • Enzyme Inhibitors / pharmacology*
  • Gene Expression Profiling
  • Humans
  • Insulin-Secreting Cells / cytology
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism
  • Male
  • Mice
  • Mice, Inbred NOD
  • Phosphorylation / drug effects
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Tubercidin / analogs & derivatives*
  • Tubercidin / pharmacology

Substances

  • Enzyme Inhibitors
  • 5-iodotubercidin
  • Dyrk kinase
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • Tubercidin