In Vivo Characterization of Calcium Signaling of NIH 3T3 Fibroblast Cells in Response to Growth Factors

Calcium is a vital ion in biological systems. It works to regulate and monitor a multitude of processes from macroscopic functions such as muscle contraction to microscopic processes such as cell proliferation through a complex signaling system. A signaling cascade is initiated when a stimulus binds to a receptor that generates calcium release which serves to activate a specific cellular function. The binding of growth factors to receptors located on the cell membrane can lead to activation of transcription factors. In addition, previous biological studies concerning a strain of polyomavirus have also found that certain transcription factors, namely c-myc, c-jun, c-fos, and JE (growth factor inducible genes) accumulate immediately after infection with the virus. As such, the focus of this thesis was to characterize the nature of calcium responses to dosages of growth factor in efforts to lay a foundation for future investigations of growth factors and infection with polyomavirus in NIH 3T3 fibroblast cells. Cells were treated with varying concentrations of growth factor and responses were monitored in vivo with one of two genetically-encoded sensors—D3cpv pc3’ (targeted to the cytosol) or D3cpv nuc (targeted to the nucleus). Efforts were made to optimize transfection efficiency, characterize the nature of the responses, as well as to lay a basic foundation of knowledge to use in later infections with polyomavirus