Beta-cell growth: an unusual paradigm of organogenesis that is cyclin D2/Cdk4 dependent

Cell Cycle. 2006 Feb;5(3):234-7. doi: 10.4161/cc.5.3.2399. Epub 2006 Feb 9.


Improved understanding of the signals that regulate growth and maintenance of adult beta-cells remains one of the main challenges in diabetes research. However, new advances in identifying the specific components involved in G1 cell cycle progression of beta-cells suggest that the molecular determinants of this pathway could ultimately be revealed. We find that cyclin D2, and to a minor degree cyclin D1, are required for adult beta-cell growth. Our observations complement previous data regarding cdk4, and suggest that mitogenic signals could act via this pathway to influence acquisition of adult beta-cell mass. Although cyclin D2/cdk4 activity is critically important for beta-cell growth, it was unclear how much ongoing replication is required to maintain beta-cell mass. Our recent long-term beta-cell labeling studies reveal that adult beta-cells could conceivably live for the life of the organism. This new paradigm of long-lived beta-cells challenges previous notions of rapid turnover of adult beta-cell mass. Thus, much remains to be learned in order to expand adult beta-cell mass in diabetes patients.

Publication types

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

MeSH terms

  • Aging*
  • Animals
  • Cell Proliferation
  • Cyclin D1 / metabolism
  • Cyclin D2
  • Cyclin-Dependent Kinase 4 / metabolism
  • Cyclins / metabolism*
  • Insulin-Secreting Cells / metabolism*
  • Mice
  • Organogenesis*
  • Pancreas / embryology
  • Pancreas / growth & development*
  • Pancreas / metabolism
  • Signal Transduction


  • Ccnd2 protein, mouse
  • Cyclin D2
  • Cyclins
  • Cyclin D1
  • Cdk4 protein, mouse
  • Cyclin-Dependent Kinase 4