We apply modern technologies to fundamental questions of epithelial cell biology. 

    The epithelial-specific mitogen ‘lacritin’ (Sanghi et al, J. Mol. Biol. ’01) provides a convenient tool. Its C-terminal amphipathic alpha helix (top left) targets the N-terminus of syndecan-1 in a heparanase-dependent manner (middle left; Ma et al, J. Cell Biol. ’06).  This stimulates mitogenic and prosecretory signaling that is biphasic, cell type selective, and involves ptyr but not ERK (top right; Wang et al, J. Cell Biol. ‘06).  Lacritin also promotes cell survival of eye epithelia (unpublished), and when topically added promotes tearing that lasts for minutes .  Chronic lacritin treatment promotes elevated tearing that is sustained for a week after treatment has ceased (Samudre et al, IOVS ’11).  This makes lacritin a potential drug for the treatment of dry eye.

    As a pleitropic growth factor apparently involved in epithelial renewal and secretion, the questions are numerous.