In normal epithelial wound repair, cells across an epithelial sheet begin a coordinated process of re-epithelialization within minutes of wounding. These coordinated behaviors are driven by a calcium wave, a rise in cytosolic calcium expanding away from the wound in a wave-like fashion. The calcium wave is evolutionarily conserved and is the earliest detectable wound response. Understanding the mechanisms of calcium influx and propagation may reveal fundamental aspects of wound detection and of cell coordination.
We observed multiple, distinct mechanisms of calcium influx and propagation around reproducible wounds in the Drosophila notum. First, extracellular calcium flows directly into cells through micro-tears on the cell surface. We were able to assess the role of micro-tears in calcium dynamics by using pulsed laser ablation, a common wounding method that generates exaggerated micro-tears. Pulsed laser ablation creates a cavitation bubble, which forms and collapses within microseconds of ablation and damages the plasma membranes of cells tens of microns away from the wound. Once inside the cells, our model predicts calcium diffuses to neighboring cells via gap junctions. Next, we observed a larger, wound-induced calcium wave that is driven by an unknown extracellular signal. This signal activates a Gαq mediated signaling cascade and induces calcium release from intracellular ER stores.
Our simple, pulsed laser ablation wounding model recapitulates a complex damage profile and reveals multiple patterns of calcium influx and propagation around a single wound. For this reason, this model has the potential to unite previous, and seemingly contradictory, findings regarding calcium dynamics in the wound healing field.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-09112017-142409 |
| Date | 14 September 2017 |
| Creators | Shannon, Erica Kristine |
| Contributors | M. Shane Hutson, Irina Kaverina, Ian Macara, Jeffrey Davidson |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-09112017-142409/ |
| Rights | restrictone, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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