Abstract
Purpose :
DJ-1 is an antioxidant protein highly expressed in RPE and inner segment of photoreceptors in retina of adult mice. Previous studies from our lab have established that lack of DJ-1 increases susceptibility of RPE and retina to oxidative stress in mice. Here, we analyzed pro-survival signaling in RPE and retina of young DJ-1 KO mice and control.
Methods :
Adult Mice (3 month-old C57BL/6J and DJ-1 KO) received a single tail vein injection of 10mg/kg body weight of NaIO3; parallel groups of mice were injected with PBS. Retina and RPE were isolated, lysed and resolved by SDS-PAGE. Proteins were excised, digested in situ with trypsin, peptides were analyzed by LC MS/MS LC-MS analysis using Orbitrap Elite mass spectrometer system. Ingenuity Pathway Analysis was used to further analyze the data. Main findings were further assayed by Western blot.
Results :
Injection of DJ-1 KO mice with low level oxidative stress (10mg/kg NaIO3) resulted in morphological retinal and RPE degeneration but not in control mice. In baseline conditions, 248 proteins were unique to control whereas only 57 proteins were unique to the DJ-1 KO RPE. Among the total detected proteins, 3 % of the proteins were significantly upregulated, 5 % of the proteins were significantly downregulated in DJ-1 KO RPE compared to control. In the retina, 158 proteins were unique to control whereas 196 proteins were unique to DJ-1 KO mice. Of the total detected proteins, 3% of the proteins were significantly upregulated, 2% were significantly downregulated in DJ-1 KO retina compared to control. Pathway analyses detected cell death and survival as one of the top molecular and cellular functions changed in the DJ-1 KO retina and RPE. Validation of the proteomics data by Western blot analysis detected lower pro-survival molecule AKT signal in DJ-1 KO RPE compared to control.
Conclusions :
Overall, our data suggests cell survival signaling mechanism decreased in the DJ-1 KO tissue.
This is a 2020 ARVO Annual Meeting abstract.