Abstract
Purpose :
Geographic atrophy (GA), the advanced form of AMD, has been linked to oxidative stress within the RPE and with low grade inflammation. The RPE-specific Sod2 knock-out mouse model of GA develops increase oxidative stress and slow retinal degeneration. Our goal is to study the role of systemic immune activation in the retinal degeneration of this mouse model of GA.
Methods :
Mice of the SOD2floxed::VMD2Cre+ genotype were injected subcutaneously with either saline or 3 mg/kg of lipopolysaccharide at 8 weeks of age. Mice were evaluated monthly by electroretinography and spectral domain optical coherence tomography for 3 months. Inflammatory cells within the retina were studied by CD45 immunofluorescence staining of frozen sections.
Results :
Systemic low-dose LPS transiently, but significantly, improved the a- and b-wave amplitudes of this mouse model between for up to 2 months when compared to saline injected mice. Concurrently, mice treated with low dose LPS also had a thicker ONL layer when compared to mice injected with saline. There was no difference in CD45 positive cells within the retinas of saline or LPS treated mice.
Conclusions :
Our results indicate that low-grade activation of the immune system can transiently protect the retina of the Sod2 KO mouse model of GA. This observation suggests that alterations of the immune system could determine the rate of retinal degeneration in the presence of chronic oxidative stress within the retina. Future studies will characterize the mechanisms that mediate this protective effect.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.