Abstract
Purpose:
The 402H variant of complement factor H (Cfh; a key regulator of complement activation) increases the risk of AMD up to 7-fold. On the other hand, oxidative stress also seems to have a key role in the pathogenesis of AMD. In this project we explore the role of Cfh in the response of the RPE and retina to acute oxidative stress.
Methods:
We generated a transgene consisting of human Cfh SCR6-8 flanked by mouse Cfh SCR1-5 and SCR9-20 (under the ApoE promoter). The resulting chimeric CfhTg mice were crossed to mCfhKO mice (deficient on mouse Cfh). We injected different pro-oxidant solutions subretinally into these transgenic mice and compared them to B6 wild type (WT) mice. ZO-1 and phalloidin staining of RPE-Choroidal flat mounts was analyzed. Toluidine blue staining of paraffin embedded retinal cross-sections was also studied. Finally, using a new method developed in our laboratory, we isolated RPE cells from mouse eyecups and isolated RNA from RPE cells of CfhTg/mCfhKO vs CfhTgCrpTg mice vs B6 mice. RNA was also obtained separately for the retina and the choroid/sclera. RT-PCR analysis of candidate inflammatory genes was then performed.
Results:
The subretinal injection of H2O2 showed increased central RPE damage both in the CfhTg and B6 WT mice compared to BSS injected controls. Excluding the area of injection, we did not observe changes in the peripheral RPE integrity due to the pro-oxidant solutions. There was no difference in the amount of RPE damage between the CfhTg and WT at the used concentrations of H2O2. We will report the effect of different dosses of this and other pro-oxidant solutions on the RPE and retina integrity, and their gene expression profile using CfhTg as well as CfhTg/humanCrpTg double Tg mice compared to WT.
Conclusions:
Complement factor H variants do not appear to have a big impact in protecting the RPE and retina from acute oxidative stress-induced injury.
Keywords: 701 retinal pigment epithelium •
412 age-related macular degeneration •
740 transgenics/knock-outs