A locally-induced increase in intracellular Ca2+ propagates cell-to-cell in the presence of plasma membrane Ca2+ ATPase inhibitors in non-excitable cells

Abstract

Intercellular Ca2+ waves are commonly observed in many cell types. In non-excitable cells, intercellular Ca2+ waves are mediated by gap junctional diffusion of a Ca2+ mobilizing messenger such as IP3. Since Ca2+ is heavily buffered in the cytosolic environment, it has been hypothesized that the contribution of the diffusion of Ca2+ to intercellular Ca2+ waves is limited. Here, we report that in the presence of plasma membrane Ca2+ ATPase inhibitors, locally-released Ca2+ from the flash-photolysis of caged-Ca2+ appeared to induce further Ca2+ release and were propagated from one cell to another, indicating that Ca2+ was self-amplified to mediate intercellular Ca2+ waves. Our findings support the notion that non-excitable cells can establish a highly excitable medium to communicate local responses with distant cells.