Oxidative Stress Alters the Morphological Responses of Myoblasts to Single-Site Membrane Photoporation

The responses of single cells to plasma membrane damage is critical to cell survival under adverse conditions and to many transfection protocols in genetic engineering. While the post-damage molecular responses have been much studied, the holistic morphological changes of damaged cells have received less attention. Here we document the post-damage morphological changes of the C2C12 myoblast cell bodies and nuclei after femtosecond laser photoporation targeted at the plasma membrane. One adverse environmental condition, namely oxidative stress, was also studied to investigate whether external environmental threats could affect the cellular responses to plasma membrane damage. The 3D characteristics data showed that in normal conditions, the cell bodies underwent significant shrinkage after single-site laser photoporation on the plasma membrane. However for the cells bearing hydrogen peroxide oxidative stress beforehand, the cell bodies showed significant swelling after laser photoporation. The post-damage morphological changes of single cells were more obvious after chronic oxidative exposure than that after acute ones. Interestingly, in both conditions, the 2D projection of nucleus apparently shrank after laser photoporation and distanced itself from the damage site. Our results suggest that the cells may experience significant multi-dimensional biophysical changes after single-site plasma membrane damage. These post-damage responses could be dramatically affected by oxidative stress.