INVESTIGATING STRESS SIGNALING ACTIVATION FOLLOWING ULTRASOUND IN COMBINATION WITH MICROBUBBLES AND CORONAVIRUS STRESS

Candidate: Louis Lo
Supervisor: Dr. Costin Antonescu; Dr. Roberto Botelho; Dr. Raffi Karshafian        

ABSTRACT

Cellular stress responses are a critical processes of cell physiology necessary to adapt to insults and facilitate cell survival. If the insult is too great and cannot be overcome, cells undergo cell death responses. Inducing cellular stress by targeting key biochemical mechanisms with pharmacological compounds to facilitate cell death is the core strategy to treat diseases such as cancers and coronavirus. In order to better develop more effective treatments, understanding the molecular mechanisms and interactions of these stress response pathways which are induced by the specific insult is needed. Herein, we explore how cells respond and recover from insults of ultrasound in combination with microbubbles (USMB) or coronavirus infection. We focus on uncovering the response from some proteins involved in canonical stress pathway which include AMPK, p53, and the family of MAPKs. Following USMB induced stress, we found that USMB alters steady-state levels of amino acids, glycolytic intermediates, and citric acid cycle intermediates, suggesting that USMB imposes metabolic stress on cells. We find that AMPK plays a central role in regulating cell fate, cell cycle status, and proliferation following USMB treatment. We also identified that USMB treatment induces an AMPK dependent p53 response and the activation of the family of MAPKs proteins in both cancerous and non-cancerous cell types. Following coronavirus induced stress, we find that both AMPK activation induced either through USMB or pharmacological compounds has little effect on reducing viral infection and propagation. 

We show that coronavirus infection alters a number of metabolic associated proteins in the cell. We identified two novel compounds, Compound C and SBI-0206965, originally designed to inhibit aspects of metabolism, can be repurposed to substantially reduce coronavirus infection and replication. However, we demonstrated that these compounds appear to act in an AMPK independent mechanism which warrants the need for further investigation. Overall, the work presented herein identified and highlights the role of key proteins which respond to USMB and coronavirus insults. This reveals new therapeutic strategies for targeting and enhancing cell death to treat certain forms of cancers and coronavirus infection.