Expression of proteoglycan decorin in neural retina

PURPOSE. To identify the expression of chondroitin/dermatan sulfate proteog lycan decorin in retina and to elucidate its changes during development and ischemia-reperfusion. METHODS. Expression of decorin in rat retina was investigated by reverse tr anscription-polymerase chain reaction (RT-PCR) and immunohistochemistry. Di stributional changes during development and transient ischemia in model eye s also were investigated by immunohistochemical experiments. RESULTS. Gene expression of decorin core protein was identified in rat reti na by RT-PCR. Decorin immunoreactivities were shown throughout the retina, especially in the ganglion cell layer. In developing rat retinas, at embryo nic stages (embryonic day IG), decorin was distributed uniformly throughout the retina. As retina matured, the intensity of decorin immunostaining in retinal inner layers and retinal pigment epithelium increased. Furthermore, in experimental transient retinal ischemia, after transient downregulation of the decorin core protein gene between 24 and 48 hours after the ischemi a, recovered (or increased) expression was shown by semiquantitative RT-PCR experiments. Immunohistochemical studies revealed strong decorin immunorea ctivities in the damaged inner layers 1 week later. CONCLUSIONS. The expression of decorin was identified in adult and developi ng rat retina. The distributional changes of decorin during the retinal dev elopment suggest that this proteoglycan may play a role in the differentiat ion of retinal ganglion cells. Moreover, in rat ischemia-reperfusion models , the alterations in gene expression and immunohistochemical localization s howed the contribution of this proteoglycan to the damage and repair proces ses in diseased retina.