Retinitis pigmentosa (RP) is a group of inherited eye diseases and with its prevalence of ~1:3.000-4.000, it is considered the greatest cause of blindness in the developed world. RP originates from at least 60 genes known to undergo gene mutations. These mutations affect the photoreceptors in the retina to undergo degeneration by a still elusive mechanism(s). The symptoms for the RP retinal degeneration are progressive vision loss, initiating with night blindness and loss of peripheral vision, due to rod photoreceptor death, and eventually loss of central vision, due to cone photoreceptor death. Today, multiple attempts have been made to develop therapies for RP and some have made it to the clinical stage. However, a fully developed therapy for multiple types of RP is currently not available, why it is crucial to reveal the pathological mechanisms in as high detail as possible, for future therapy development.

We have reported that an enzyme system, the cGMP system (cyclic guanosine-monophosphate; cGMP), plays a critical role in the degeneration and that cGMP levels are increased in the RP photoreceptors. These and other findings show that the cGMP system is a target for neuroprotective measures.

Aim:

In this project the aim is to address the disease related role and consequences of the high photoreceptor cGMP, with particular emphasis on the cGMP interactors.

The high cGMP can be expected to interact with specific proteins. Traditional cGMP interaction partners include cyclic nucleotide-gated channels (CNGs) and cGMP-dependent protein kinases (PKGs), but it is highly likely that also other cGMP interactors exist. The relevant cGMP interactors in the RP disease are still not described in detail, so their disclosure would open up possibilities for better therapy development.