Abstract 1614 Aptamer Selection for an Anti-Superoxide Dismutase 1 (SOD1) Aptamer for Tracking SOD1 Migration and Aggregation in Neurodegenerative Diseases

While it is known that superoxide dismutase 1 (SOD1) is associated with neurodegenerative diseases, there is much to learn about the mechanism of toxicity and migration of this protein in the human body. The SOD1 protein is an antioxidant enzyme that protects cells from the toxicity of reactive oxygen species (ROS). SOD1 converts these chemical products of cells that are highly reactive, to less harmful chemicals. However, mutant forms of SOD1 protein are implicated in the gain of toxicity in neuron cells in neurodegenerative conditions such as Amyotrophic Lateral Sclerosis (ALS). ALS is characterized by the death of upper and lower motor neuronal cells that result in hypokinesia and immobilization of the human body. Even though there are about 5,000 new ALS diagnoses each year in the United States and this number is currently increasing, the mechanism behind the forming of mutant SOD1 is still an ongoing area of research. This research aims to create a molecular tool, specifically an aptamer, to visualize the migration and aggregation of SOD1 proteins in neuron cells. To achieve that, this research's focus is to find and develop an aptamer sequence as an intracellular tracking tool of SOD1. Aptamers bind their targets with high binding affinity and specificity and are composed of oligonucleotides. To study the migration of SOD1, the anti-SOD1 aptamer will be fluorescently labeled so that it will be visualized in live-cell imaging techniques. This approach will produce a low-cost, easy storage, and effective molecular tool to study and track the migration and other interactions of SOD1 in real-time. To develop this molecular tool, this work will employ the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique to find an aptamer against SOD1. The study will utilize the bead-based SELEX to partition the SOD1-bound RNA sequences from the unbound sequences. In general, SELEX involves partition, amplification, and purification steps. In addition, the conditions of each round of selection, such as pH at 7.4 and 37°C temperate, were kept constant as those mimicked the conditions of the human body. Iterative rounds of SELEX will be conducted to enrich the oligonucleotide pool and ultimately isolate aptamers from the original N71 RNA pool. This research is currently in its fifth round of SELEX out of potentially 5 to 20 SELEX rounds. The enriched RNA pool is currently being sequenced using Next Generation Sequencing. This will determine if more rounds of selection are needed or if the research can move to the binding assay step and work can begin on further developing the aptamer sequence. The further success and development of this study will allow real-time visualization of SOD1 protein and give medical and biomedical researchers a better understanding of the association of SOD1 enzyme in ALS, Alzheimer's, Parkinson's, or other neurodegenerative diseases. This study was supported by the UT Freshman Research Initiative and the S-STEM fellowship funded by NSF.