|
|
||||||||
HORMONES AND SIGNALING
Departments of 1Molecular and Integrative Physiology, 2Cellular and Developmental Biology, and 3Internal Medicine, The University of Michigan Medical School, Ann Arbor, Michigan
Submitted 20 September 2006 ; accepted in final form 3 November 2006
Endogenous CCK release induced by a synthetic trypsin inhibitor, camostat, stimulates pancreatic growth; however, the mechanisms mediating this growth are not well established. Early response genes often couple short-term signals with long-term responses. To study their participation in the pancreatic growth response, mice were fasted for 18 h and refed chow containing 0.1% camostat for 124 h. Expression of 18 early response genes were evaluated by quantitative PCR; mRNA for 17 of the 18 increased at 1, 2, 4, or 8 h. Protein expression for c-jun, c-fos, ATF-3, Egr-1, and JunB peaked at 2 h. Nuclear localization was confirmed by immunohistochemistry of c-fos, c-jun, and Egr-1. Refeeding regular chow induced only a small increase of c-jun and none in c-fos expression. JNKs and ERKs were activated 1 h after camostat feeding as was the phosphorylation of c-jun and ATF-2. AP-1 DNA binding evaluated by EMSA showed a significant increase 12 h after camostat feeding with participation of c-jun, c-fos, ATF-2, ATF-3, and JunB shown by supershift. The CCK antagonist IQM-95,333 blocked camostat feeding-induced c-jun and c-fos expression by 67 and 84%, respectively, and AP-1 DNA binding was also inhibited. In CCK-deficient mice, the maximal response of c-jun induction and AP-1 DNA binding were reduced by 64 and 70%, respectively. These results indicate that camostat feeding induces a spectrum of early response gene expression and AP-1 DNA binding and that these effects are mainly CCK dependent.
CCK; camostat; c-jun; c-fos; AP-1
This article has been cited by other articles:
![]() |
G. T. Gurda, L. Guo, S.-H. Lee, J. D. Molkentin, and J. A. Williams Cholecystokinin Activates Pancreatic Calcineurin-NFAT Signaling In Vitro and In Vivo Mol. Biol. Cell, January 1, 2008; 19(1): 198 - 206. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |