Suppression of Salivary Gland Apoptosis by AKt

DESCRIPTION: (provided by applicant) 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.