Identification of molecules from dying cells that act as signals to promote proliferation of surrounding cells

To elucidate the mechanisms underlying epithelial homeostasis, we explored molecules that might serve as “danger” signals in mediating epithelial regeneration with microarray. We hypothesize that soluble factors may have been released from damaged cells to stimulate the proliferation of surviving epithelial cells. In elucidating the mechanism of dying cell-to-surviving cell communication using normal rat kidney NRK-52E epithelial cells, we observed gene expression profiles in these cells after the induction of cell death using hydrogen peroxide. The results demonstrated up-regulation of Interleukin-6, Heme oxygenase-1 and Hypoxia inducible factor-1 alpha in dying cells.