Activation of caspase-3 in axotomized rat retinal ganglion cells in vivo.

Recently, we have shown that inhibition of caspase-3-like caspases is the most effective treatment strategy to protect adult rat retinal ganglion cells from secondary death following optic nerve transection. In the present study, we localized active caspase-3 in axotomized retinal ganglion cells in vivo and demonstrated a co-localization of the active p20 fragment and TUNEL-staining in some of these cells. In line with this, we detected an enhanced cleavage and activity of caspase-3 protein in retinal tissue after lesion, while caspase-3 mRNA expression remained unchanged. These data suggest caspase-3 as an important mediator of secondary retinal ganglion cell death following axotomy in vivo.