Characterization of Calcium-Mediated Intracellular and Intercellular Signaling in the rMC-1 Glial Cell Line

摘要

Retinal Miiller glial cells, in addition to providing homeostatic support to retinal neurons, have been shown to engage in modulation of neuronal activity and regulate vasomotor responses in the retina, among other functions. Calcium-mediated signaling in Miiller cells has been implicated to play a significant role in the intracellular and intercellular interactions necessary to carry out these functions. Although the basic molecular mechanisms of calcium signaling in Miiller cells have been described, the dynamics of calcium responses in Miiller cells have not been fully explored. Here, we provide a quantitative characterization of calcium signaling in an in vitro model of Miiller cell signaling using the rMC-1 cell line, a well-established line developed from rat Miiller cells. rMC-1 cells displayed robust intracellular calcium transients and the capacity to support calcium transient-mediated intercellular calcium waves with signaling dynamics similar to that reported for Miiller cells in in situretinal preparations. Furthermore, pharmacological perturbations of intracellular calcium transients with thapsi-gargin and intercellular calcium waves with purinergic receptor antagonists and gap junction blockers (PPADS and FFA, respectively) suggestthat the molecular mechanisms that underlie calcium signaling in rMC-1 cells has been conserved with those of Miiller cells. This model provides a robust in vitro system for investigating specific mechanistic hypotheses of intra- and intercellular calcium signaling in Miiller cells.