Abstract
Purpose :
Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies that leads to blindness. Mutations in over 60 genes/loci have been associated to RP. Despite of the heterogeneous mutational etiology, RP courses, in most of the cases, with dysfunction and degeneration of photoreceptors. Reactive micro and macrogliosis and an inflammatory response are common traits that contribute to the pathogenesis of the disease. The aim of our study is to characterize the contribution of the innate immunity response to the RP physiopathology. In particular, in the current study we evaluated the implication of the Toll Like Receptor 4 (TLR4).
Methods :
We compared the retinal degeneration time-course of the rd10 mouse null for the Tlr4 gene with the rd10 control. Retinal function was evaluated by ERG-recordings and the cytoarchitecture of the retina was analyzed by immunostaning of cryosections. Gene expression was assessed by RT-qPCR.
Results :
Tlr4 expression in rd10 mouse model showed up to six fold increase starting at P18, an early stage of degeneration. Visual function in the interval P26-47 declined significantly slower in TLR4-/- rd10 mice than in rd10 controls. Moreover ONL thickness was partially preserved in TLR4-/- rd10 mouse retinas, whereas the expression of proinflammatory cytokines showed a trend to decrease in TLR4 deficient animals.
Conclusions :
TLR4 deficiency attenuates molecular, cellular and functional signs of retinal degeneration in the rd10 mouse model of RP
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.