How photoreceptor cells go through the process of cell death has been an outstanding question. The authors of this paper by Yusuke Murakami, Hidetaka Matsumoto, Miin Roh, Jun Suzuki, Toshio Hisatomi, Yasuhiro Ikeda, Joan W. Miller, and Demetrios G. Vavvas have further defined the process and identified the receptor interacting protein kinase (RIP) pathway as a possible target for intervention in patients with retinitis pigmentosa (RP). The authors used the rd10 mouse model, a mouse model of retinitis pigmentosa to examine the cell death process. They defined RIP kinase as a mediator of necrotic cell death in cones. RIP3, has been defined as they key regulator of programmed necrosis and its expression was elevated in rd10 retinas during cone photoreceptor death and not rod photoreceptor death. Furthermore, the cone photoreceptor cell death was rescued by RIP3 deficiency and by pharmacological treatment with RIPkinase inhibitors.
Its an exciting study that points the way for drug based treatments of retinitis pigmentosa and their allied diseases that affect cone photoreceptors. We’ve shown again and again, most recently in a large eye model of retinitis pigmentosa, that so long as cone photoreceptors are present, the retinal remodeling events that ultimately irreversibly revise the retinal architecture and wiring are largely held at bay. When cones are lost, so is the retina.