The MDM2 T309G mutation in primary human retinal epithelial cells enhances experimental proliferative vitreoretinopathy

Abstract

Purpose : The murine double minute 2(MDM2), whose human homologue is also called HDM2, is a critical negative regulator of the p53 tumor suppressor and the G309 allele of singe nucleotide polymorphisms (SNPs) in the MDM2 promoter locus is associated with a higher risk of proliferative vitreoretinopathy (PVR). We have shown that the MDM2 T309G mutation created using clustered regularly interspaced short palindromic repeats (CRISPR)/associated endonuclease (Cas)9 enhances vitreous-induced expression of MDM2 and survival of primary human primary retinal pigment epithelial (hPRPE) cells. The goal of this project is to determine whether this MDM2 mutation contributes to the development of experimental PVR.

Methods : Human vitreous from PVR patients (HV) was used to treat the hPRPE cells with MDM2 T309T or T309G, and the expression of MDM2 and p53 in the treated cells was examined by western blot. The vitreous-induced cellular responses such as contraction were assessed, PVR was evaluated by intravitreal injection of the hPRPE cells with MDM2 T309T or T309G into rabbit eyes.

Results : Western blot analysis indicated that HV enhanced a increase (1.7 ± 0.2 fold) in MDM2 and a significant decrease in p53 in the PRPE cells with the MDM2 T309G compared to those with MDM2 T309T. In addition, we found that HV promoted cell contraction in the PRPE cells with the cells expressing MDM2 T309G contracting more than cells with MDM2 T309T. Furthermore, MDM2 T309G enhanced the development of PVR in the rabbit model.

Conclusions : The MDM2 SNP G309 contributes to the development of experimental PVR.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.