CELL-ADHESION TO CRYSTAL-SURFACES - ADHESION-INDUCED PHYSIOLOGICAL CELL-DEATH

Cultured epithelial cells interact massively rapidly and stereospecifi cally with the {011} faces of calcium (R,R)-tartrate tetrahydrate crys tals. It was suggested that the massive rapid adhesion represents an e xaggerated and isolated form of the first initial events in the attach ment of cultured cells to conventional tissue culture surfaces (Hanein , et al., Cells and Materials, 5, 197-210; 1995). Attachment is howeve r not followed by normal cell spreading and development of focal adhes ions, but results in massive cell death. In this study, the fate of th e crystal-bound cells was characterized by electron microscopy, flow c ytometry and microscopic morphometry and was found to display the char acteristics of physiological cell death. We show that the direct inter action with the highly homogenous and repetitive {011} faces per se do es not trigger the transduction of lethal transmembrane signals. We su ggest that the excessive direct interactions between the cell membrane and the crystal, by impairing cell motion, prevent the evolution of R GD-dependent cell adhesion. This implies that the deprivation of prope r extracellular matrix (ECM)-receptor contacts of substrate-attached e pithelial cells eventually triggers physiological cell death.