PROFESSOR OPHTHALMOLOGY AND VISUAL SCIENCES CELL BIOLOGY AND PHYSIOLOGY

Our studies focus on the cell and molecular basis of lens transparency. Loss of transparency (cataract) is the most common cause of blindness in the world. A particularly interesting feature of lens development is the programmed elimination of cytoplasmic organelles from cells in the light path. We are investigating the events that trigger organelle loss and aim to determine the molecular identity of the proteases and nucleases that facilitate removal of organelles. The lens grows throughout life prompting many investigators to speculate that the tissue contains a contingent of stem cells. We are using in vivo lineage tracking strategies to investigate this hypothesis and model the growth of the lens. Preliminary data suggest a link between clonal growth of lens cells and the development in later life of cortical cataracts. Fiber cells, the terminally differentiated cells that account for most of the volume of the lens, persist throughout life. Our data suggest that these cells are unusually resistant to apoptotic stimuli. We are currently analyzing the role of IAPs (inhibitor of apoptosis proteins) in lens cell longevity using a microarray-based screening protocol in conjunction with inducible gene knockout in mice