| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Comparative Biosciences, University of Wisconsin School of Veterinary Medicine, Madison, WI, USA
* To whom correspondence should be addressed. E-mail: careyh{at}vetmed.wisc.edu.
Mammalian hibernation is associated with several events that can affect programmed cell death (apoptosis) in non-hibernators, including marked changes in blood flow, extended fasting and oxidative stress. However, the effect of hibernation on apoptosis is poorly understood. Here we investigated apoptosis and expression of proteins involved in apoptotic pathways in intestinal mucosa of summer and hibernating ground squirrels. We used TUNEL to identify possible apoptotic enterocytes in small intestine of summer squirrels and hibernating squirrels throughout the winter. Nuclear TUNEL staining increased as hibernation progressed, but the staining pattern was diffuse and not accompanied by chromatin condensation or apoptotic bodies. Electrophoresis of mucosal DNA revealed no ladders typical of apoptosis. Nuclear levels of pro-apoptotic p53 protein were 4-fold less in hibernators compared with summer squirrels. A 12-fold increase in anti-apoptotic Bcl-xL compared with a 2-fold increase in pro-apoptotic Bax suggested a balance in favor of antiapoptotic signaling in hibernators. There was no change in Bcl-2 protein expression but phospho-Bcl-2 increased in hibernator mucosa. Hibernation had minimal effects on expression of active caspase-8 or -9, whereas caspase-3 specific activity was lower in hibernators during an interbout arousal compared with summer squirrels. Expression of the pro-survival protein Akt increased 20-fold during hibernation but phospho-Akt was not altered. These data provide evidence for enhanced expression of anti-apoptotic proteins during hibernation that may promote enterocyte survival in a pro-oxidative, pro-apoptotic environment.
This article has been cited by other articles:
|
|
 |
|
  S. L. Martin, L. E. Epperson, J. C. Rose, C. C. Kurtz, C. Ane, and H. V. Carey Proteomic analysis of the winter-protected phenotype of hibernating ground squirrel intestine Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2008; 295(1): R316 - R328. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Yan, B. M. Barnes, F. Kohl, and T. G. Marr Modulation of gene expression in hibernating arctic ground squirrels Physiol Genomics, January 17, 2008; 32(2): 170 - 181. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. C. van der Peet-Schwering, A. J. M. Jansman, H. Smidt, and I. Yoon Effects of yeast culture on performance, gut integrity, and blood cell composition of weanling pigs J Anim Sci, November 1, 2007; 85(11): 3099 - 3109. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. J. Serkova, J. C. Rose, L. E. Epperson, H. V. Carey, and S. L. Martin Quantitative analysis of liver metabolites in three stages of the circannual hibernation cycle in 13-lined ground squirrels by NMR Physiol Genomics, September 11, 2007; 31(1): 15 - 24. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. C. Kurtz, S. L. Lindell, M. J. Mangino, and H. V. Carey Hibernation confers resistance to intestinal ischemia-reperfusion injury Am J Physiol Gastrointest Liver Physiol, November 1, 2006; 291(5): G895 - G901. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
