Abstract
Presentation Description :
Purinoreceptors are known for their role in wound repair in the corneal epithelium. These receptors are a diverse family of proteins and include both ion-channel proteins and G-protein coupled receptors. In the cornea these receptors appear to be inversely regulated at a transcript level. P2X7 receptor mRNA is significantly higher in corneal epithelium from diabetics than from age-matched controls. This receptor is an ion channel protein and displays a proximal-distal polarity after injury that is manifested in the pre-Type II diabetic model - the DiO mouse. To determine how or if the purinoreceptors mediate cell communication, calcium mobilization and wound repair experiments were performed using live cell imaging and the results will be discussed. Results were examined both at the time of injury and during times of active migration. To examine the large data sets, scripts were written to understand the cell behavior. We found that when the P2Y2 is stimulated, almost all of the cells respond compared to stimulation of the P2X7 receptor. However, the signals elicted by activation of the P2Y2 receptor are not well coordinated. In contrast, there is a signficantly higher probability that cells will communicate when the P2X7 receptor is stimulated. There was a similar probability of communication after injury. The presence of Ca2+ mobilizations between neighboring cells also correlated with changes in cell morphology that are necessary for cell motility. While there is no significant change in the probability that cells communicate in the presence of gap junctions, inhibition of pannexin channels, which are associated with P2X7, altered the pattern of cell-cell communication and motility. A similar set of analyses were employed to examine cell-communication at the wound edge over time using cell and tissue based live cell imaging experiments.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.