Is Decreased Ability to Divide Due to Increased Oxidative DNA Damage?
The characteristics exhibited by central corneal endothelial cells from older individuals are very similar to characteristics of cells that have entered senescence – a healthy life-stage in which cells are inhibited from dividing, to prevent tumor formation. In searching the literature for an explanation for the age-related decrease in corneal endothelial cell proliferative capacity, the Joyce lab found that oxidative DNA damage from high metabolic activity and/or from light can induce cellular senescence and decrease proliferative capacity. This type of damage is already considered a potential cause of dysfunction in the ocular lens and in retinal pigment epithelial cells. The “pump” activity of the corneal endothelium requires that the cells be highly metabolically active and may thus cause increased oxidative stress. In addition, since light passes through the cornea, including the endothelial cells, it is possible that light also contributes to an age-dependent accumulation of oxid
