Molecular Imaging Approaches toward Optical Detection of Hydrogen Peroxide and Copper in Murine Models of Disease
- Author(s): Van de Bittner, Genevieve Crystal
- Advisor(s): Chang, Christopher J.
- et al.
The study of biological processes involved in the development and progression of disease has the potential to uncover new treatments or cures. While there are many techniques to study biological analytes involved in disease states, molecular imaging offers tools that are amenable to imaging biological processes as they occur in living systems. Previously developed fluorescent molecular imaging tools have lead to an improved understanding of the roles of both hydrogen peroxide (H2O2) and copper in both normal physiological processes and in disease. However, most of these tools have been limited to the study of H2O2 and copper in cells or tissues. A more comprehensive understanding of molecular disease processes involved in disease states can be gleaned by studying animal models of human disease, as the affects of the disease on the entire organism can be monitored. This dissertation describes the design, synthesis, and characterization of bioluminescent and fluorescent molecular imaging tools for the detection of H2O2 and copper, and their application to the detection of these analytes in murine models of disease. In a first demonstration, Peroxy Caged Luciferin-1 is developed using a firefly luciferin probe scaffold and utilized to monitor increased H2O2 production in androgen-sensitive prostate tumors following stimulation with a growth-inducing compound, testosterone. Using a new approach for firefly luminescence imaging, in situ formation of firefly luciferin, two unique probes, Peroxy Caged Luciferin-2 and IETDC, are developed for simultaneous imaging of H2O2 and caspase 8 activity in a model of sepsis. Development of a third luminescence-based probe for H2O2 detection, Peroxy Caged Luciferin-3, offers a tool for the detection of H2O2 in the brain of mice, with possible applications for studying H2O2 during seizure. Finally, development of a near-infrared fluorescent probe for detection of copper in vivo is discussed and applied to the detection of alterations in copper levels during the development and treatment of a murine Wilson's disease model.