Research Paper|Volume 2, Issue 11|pp 785—790

CENP-A, a protein required for chromosome segregation in mitosis, declines with age in islet but not exocrine cells

Seung-Hee Lee¹, Pamela Itkin-Ansari^2,³, Fred Levine¹

¹Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
²Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
³Neurosciences, Aging, and Stem Cell Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA

Received: October 13, 2010Accepted: October 27, 2010Published: October 29, 2010

Copyright: © 2010 Lee et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Beta-cell replication dramatically declines with age. Here, we report that the level of CENP-A, a protein required for cell division, declines precipitously with age in an islet-specific manner. CENP-A is essentially undetectable after age 29 in humans. However, exocrine cells retain CENP-A expression. The decline in islet-cell CENP-A expression is more striking in humans than in mice, where CENP-A expression continues to be detectable at low levels even in elderly mice. The mechanism by which CENP-A declines appears to be post-transcriptional, as there was no correlation between CENP-A mRNA levels and age or islet purity. This finding has implications for efforts to induce beta-cell replication as a treatment for diabetes.