The induction of apoptosis is an important event in mammalian development; however, apoptosis of salivary gland cells resulting from head and neck irradiation, chemotherapeutic drugs, or autoimmune diseases ultimately decreases the quality of life for these patients. The goal of this project is to define the signaling pathways activated in the salivary glands by various apoptotic stimuli and determine if these events can be suppressed.
Specific aim 1 identifies the activation of the anti-apoptotic protein kinase Akt by growth factors in C5 parotid and C6 submandibular cell lines and the protection activated Akt confers after an apoptotic insult (etoposide, taxol, irradiation, and FasL). Apoptosis will be quantitated after each stimulus by flow cytometry to measure Sub G1 fraction, caspase 3 activation, TUNEL assay, and immunoblotting for Akt substrates. Transgenic mice have been generated to express a constitutively active form of the pro-survival molecule Akt (Myr-Akt) in the salivary glands.
Specific aim 2 will assess the ability of the primary murine salivary gland acinar cells from the Myr-Akt mice to suppress apoptosis.
Specific aim 3 examines the apoptotic response of the transgenic mice to various stimuli including: isoproterenol, irradiation, and FasL. After each stimulus, salivary gland flow rate will be measured and salivary gland tissues will be analyzed by standard histology, TUNEL staining, and immunoblotting for Akt substrates and changes in salivary protein concentrations. These studies will provide greater insight to the understanding of this tissue and potentially provide clinical treatment of cancer-induced apoptosis in salivary glands.
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|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|
|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|