Research Abstract:
The lens of the eye functions to form a sharply focused image on the retina. To do this, it must remain transparent throughout life and flexible enough to allow the eye to accommodate properly. Loss of lens transparency (cataract) is the most common cause of blindness in the world. Age-related “stiffening” of the lens affects almost everyone over age 50 and results in an inability to focus on near objects (presbyopia).
Studies in my laboratory are aimed at understanding the cellular basis of transparency and accommodation. One project concerns the developmental processes that contribute to lens transparency. 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 the molecular mechanisms that underlie this process.
The cell and molecular basis of accommodation is not well understood. We recently identified novel elements of the lens cytoskeleton that may play a role in this process. To test this hypothesis, we have developed a number of approaches that take advantage of the transparent properties of the lens. For example, we use confocal microscopy to visualize the distribution of exogenous fluorescent proteins expressed in single cells of the living lens. We are combining cell biological approaches such as these with the classical techniques of physiological optics to provide a more complete understanding of the cellular mechanisms that operate during accommodation and presbyopia.
Selected Publications:
Shi Y, Barton K, De Maria A, Petrash JM, Bassnett S. The stratified syncytium of the vertebrate lens. J Cell Sci 2009 122:1607-15.
De Maria A, Shi Y, Kumar NM, Bassnett S. Calpain expression and activity during lens fiber cell differentiation. J Biol Chem 2009 284:13542-50.
Bassnett S. On the mechanism of organelle degradation in the vertebrate lens. Exp Eye Res 2009 88:133-9.
De Maria A, Bassnett S. DNase IIbeta distribution and activity in the mouse lens. Invest Ophthalmol Vis Sci 2007 48:5638-5646.
Shiels A, King JM, Mackay DS, Bassnett S. Refractive defects and cataracts in mice lacking lens intrinsic membrane protein-2. Invest Ophthalmol Vis Sci 2007 48:500-508.
Last Updated: 08/27/2009 |