M. Joseph Costello, PhD
Education and Training
George Washington University, B.S.E., 1964
Duke University, PhD, 1971
Duke University, Postdoctoral, 1971-1974
The Centre de Génétique Moléculaire, Postdoctoral, 1974-1975
Areas of Interest
The main research project is to determine the role of intercellular junctions in normal development, cell aging and cataract formation in human and animal lenses. The lens is an avascular epithelioid tissue contained within a capsule. Unlike other stratified epithelia, the lens does not slough off cells. Thus, the adult lens contains a gradient of aged fiber cells with the most recently formed cells on the lens surface and the oldest cells in the lens center. Because the lens is avascular, fiber cells communicate through extensive gap junctions in order to exchange small molecules, such as water, nutrients, second messengers and toxins. The lens has the highest density of gap junctions of any mammalian tissue and, in some regions, gap junctions can cover up to 50% of the cell surface. Our major interest is in the age-related changes in gap junctions and their role in cell functions in the older cells in the lens interior. Our current goal is to obtain more detailed data on gap junction function using laser confocal light microscopy combined with measurements of intracellular dye transfer.