Abstract
Purpose :
The underling mechanism of retinal pigment epithelium (RPE) atrophy in geography atrophy (GA) remains unclear. Previous work in our lab demonstrated that the oxidative stress could induce RPE cell necroptosis instead of apoptosis. Here, we test the hypothesis that phosphoglycerate mutase family member 5 (PGAM5), a mitochondrial outer membrane protein, plays a role in oxidant-induced necroptosis in RPE cells.
Methods :
A Crispr-cas9 system was used to knockout (KO) PGAM5 gene in APRE-19 cells. PGAM5 siRNA was also used to knockdown PGAM5 transiently. MTT and Neutral Red assays were employed to compare the anti-oxidative ability of wild type and PGAM5 KO cells. Necroptosis of ARPE-19 cells was visualized after RIP3K-GFP co-transfection, propidium Iodide (PI) and other necroptosis marker staining. Real-time PCR was used to exam the expression level of anti-oxidant genes regulated by transcription factor NRF2. Pgam5 knockout mice were used to evaluate the function of Pgam5 in vivo.
Results :
We provide evidence that PGAM5 is critical in regulating resistance to oxidative stress in ARPE-19 cells. Knockout of PGAM5 in ARPE-19 cells protect the cells from NaIO3-induced necroptosis through NRF2-mediated pathways. Mechanistically, PGAM5 knockout prevents mitochondrial fragmentation in RPE cells. A battery of anti-oxidant genes, including NRF2, FOXO4 and SOD1, were upregulated in PGAM5 KO cells.
Conclusions :
PGAM5 regulates RPE cell resistance to oxidative stress through a NRF2-mediated anti-oxidant gene program, which may have therapeutic implications for GA in humans.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.