Alterations in programmed cell death or apoptosis contribute to developmental abnormalities, autoimmune disease, and cancer. This is most clearly demonstrated by the discovery that the Bcl-2 plays a critical role in the development of B-cell lymphoma in humans. This may also be true in the case of salivary gland where the development of salivary gland tumors might involve genetic changes that stimulate proliferation and suppress apoptosis. Likewise, Sjogrens syndrome appears to involve the loss of salivary acinar cells by an autoimmune response that results in Fas-induced apoptosis. These observation suggest that understanding the signaling me3chanisms that regulate apoptosis in the salivary gland is fundamental to understanding the biology of this tissue. This proposal will focus upon two different signaling molecules, members of the MAP kinase family, and the anti-apoptotic protein kinase AKT. Based upon our data on etoposide-induced apoptosis of salivary cell lines, we hypothesize that changes in the balance between two MAP kinase family members, ERKs and JNKs, may play an important role in determining whether a cell will undergo apoptosis. We will determine whether this is also true for two other apoptotic stimuli, Fas and x-irradiation, using both established salivary acinar cell lines and primary salivary acinar cells. Dominant negative and constitutively activated mutants of different signaling molecules will be used to determine the role of ERKs and JNKs in apoptosis. We also hypothesize that activation of AKT, either by growth factor stimulation or mutation of AKT, can suppress apoptosis induced by etoposide, x-irradiation, or Fas. This will be directed tested in salivary cell lines and primary acinar cells stimulated with various growth factors, or transduced with adenoviral vectors encoding a constitutively activated mutant of AKT. Finally, transgenic mice that express a constitutively activated form of AKT in the salivary gland will be used to determine the role that AKT plays in suppressing apoptosis in this tissue. The effects of AKT expression tissue homeostasis in vivo will be assessed. Furthermore, we will examine the effects of specific apoptosis stimuli upon salivary acinar cells from these transgenic both in vitro and in vivo. These studies will provide information about pathways that regulate apoptosis in salivary acinar cells which is fundamental to our understanding of this complex tissue.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Program Projects (P01)
Project #
5P01DE012798-03
Application #
6564071
Study Section
Special Emphasis Panel (ZDE1)
Project Start
2002-02-01
Project End
2003-01-31
Budget Start
Budget End
Support Year
3
Fiscal Year
2002
Total Cost
$115,989
Indirect Cost
Name
University of Colorado Denver
Department
Type
DUNS #
065391526
City
Aurora
State
CO
Country
United States
Zip Code
80045
Limesand, Kirsten H; Said, Sherif; Anderson, Steven M (2009) Suppression of radiation-induced salivary gland dysfunction by IGF-1. PLoS One 4:e4663
Limesand, Kirsten H; Schwertfeger, Kathryn L; Anderson, Steven M (2006) MDM2 is required for suppression of apoptosis by activated Akt1 in salivary acinar cells. Mol Cell Biol 26:8840-56
DeVries, Tracie A; Kalkofen, Rachelle L; Matassa, Angela A et al. (2004) Protein kinase Cdelta regulates apoptosis via activation of STAT1. J Biol Chem 279:45603-12
Limesand, Kirsten H; Barzen, Katherine A; Sanders, Linda A et al. (2003) Characterization of rat parotid and submandibular acinar cell apoptosis in primary culture. In Vitro Cell Dev Biol Anim 39:170-7
Limesand, K H; Barzen, K A; Quissell, D O et al. (2003) Synergistic suppression of apoptosis in salivary acinar cells by IGF1 and EGF. Cell Death Differ 10:345-55
DeVries, Tracie A; Neville, Margaret C; Reyland, Mary E (2002) Nuclear import of PKCdelta is required for apoptosis: identification of a novel nuclear import sequence. EMBO J 21:6050-60
Matassa, A A; Carpenter, L; Biden, T J et al. (2001) PKCdelta is required for mitochondrial-dependent apoptosis in salivary epithelial cells. J Biol Chem 276:29719-28