Systemic Regulation of the Age-Related Decline of Pancreatic β-Cell Replication

  1. Yuval Dor1
  1. 1Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
  2. 2Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
  1. Corresponding author: Yuval Dor, yuvald{at}ekmd.huji.ac.il.

Abstract

The frequency of pancreatic β-cell replication declines dramatically with age, potentially contributing to the increased risk of type 2 diabetes in old age. Previous studies have shown the involvement of cell-autonomous factors in this phenomenon, particularly the decline of polycomb genes and accumulation of p16/INK4A. Here, we demonstrate that a systemic factor found in the circulation of young mice is able to increase the proliferation rate of old pancreatic β-cells. Old mice parabiosed to young mice have increased β-cell replication compared with unjoined old mice or old mice parabiosed to old mice. In addition, we demonstrate that old β-cells transplanted into young recipients have increased replication rate compared with cells transplanted into old recipients; conversely, young β-cells transplanted into old mice decrease their replication rate compared with young cells transplanted into young recipients. The expression of p16/INK4A mRNA did not change in heterochronic parabiosis, suggesting the involvement of other pathways. We conclude that systemic factors contribute to the replicative decline of old pancreatic β-cells.

Footnotes

  • Received February 1, 2013.
  • Accepted April 22, 2013.

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