| Abstract : |
Recently H2O2 has been recognized as an important signaling molecule in many physiological processes including epithelial wound response. Here I analyze the activation mechanism and spatio-temporal dynamics of H2O2 response to wounding in MCF10-A mammalian epithelial cells. Previous work on zebrafish and drosophila has demonstrated a clear H2O2 gradient in response to wounding. However, the activation mechanism of H2O2 in these two model systems differs. Furthermore, the initial signal that activates wound induced H2O2 signaling is unknown. Therefore how the H2O2 gradient is generated in mammalian systems is unclear. To experimentally test for wound-specific activation of H2O2 we developed a specialized microfluidic device to ensure reproducible, convection-free wounds. HyPer3 expressing cells wounded in our wounding device revealed a H2O2 response to wounding. This response occurred rapidly, beginning within the first two minutes of wounding, but extended for approximately 90 minutes at distances greater then 1mm. We analyzed extracellular ATP, which was the previously hypothesized candidate for initial activation of H2O2. Experiments done in our lab indicate that this may not be the mechanism of the observed H2O2 response. Therefore, the specific wound induced signal that activates H2O2 response is unknown. My future goal is to identify the wound induced signal and elucidate the specific mechanism of activation of H2O2 during wound response. The emerging mechanistic understanding of H2O2 activation can assist in the designing of drugs or treatments that target the initial wound response signals, specifically the H2O2 mechanism, to ensure proper and efficient healing. |