Jia Qi Chen

Exploring the Effect of Mitochondria Morphological Damage on Mitochondrial Membrane Potential in Anastatic Cells

During apoptotic cell death, mitochondrial outer membrane permeabilization (MOMP) occurs. MOMP results in the release of cytochrome c into the cytosol, triggering caspase activation. Studies show that cancer cells can survive caspase activation following transient apoptotic stimuli during a process called anastasis. However, the mitochondrial network has not been well documented in anastatic cells. Instead of healthy and interconnected mitochondrial networks, we observed a clump of mitochondria near the nucleus in 35% of surviving cells. After 3 days, cells show a decrease in the mitochondrial membrane potential. My research aims to categorize mitochondrial phenotypes and explore potential causes of decreased mitochondrial membrane potential in anastatic cells. We hypothesize that the decreased mitochondrial membrane potential is due to mitochondria morphological defect. Co-treatment of STS-QVD results in a higher frequency of anastatic cells in the population compared to STS treatment alone. HeLa cell lines are co-treated with STS-QVD and images of 5 random fields of each cell line are taken with confocal fluorescent microscopy at different time points after the initial treatments. The phenotypes of the mitochondria are compared against reference phenotypes to determine the degree of mitochondrial fragmentation, which is a hallmark of morphological damage. In the next step of the project, we aim to correlate mitochondria morphological damage with TMRM (fluorescence dye that accumulates in mitochondria with intact membrane potential) intensity, and a negative correlation will suggest mitochondrial damage may contribute to the decreasing mitochondrial membrane potential in anastatic cells.